Question

The following structure has five different types of C-H bonds, mark a to e



Arrange the five C-H bonds in decreasing order of their bond energy.

• A. a>b>d>e>c
  
• B. a>c>b>d=e
  
• C. a>c>d>e>b
  
• D. a>b>c>d>e

Answer 1

The correct option is C

a>c>d>e>b

Let us assume that the H is removed as $H^{-}$ leaving compound as carbocation. More the stability of the carbocation, easy will be its formation hence less will be the bond energy of the concerned C-H bond. The type of corresponding carbocations in five different conditions is written below their structures.



Thus the stability order of these carbocations will be
$3^{\circ }Allylic>2^{\circ }Allylic>2^{\circ }>1^{\circ }>VinylicFrom\left(b\right)From\left(e\right)From\left(d\right)From\left(c\right)From\left(a\right)$